package com.bt.aspect;

import com.bt.annotation.AutoFill;
import com.bt.constant.AutoFillConstant;
import com.bt.context.BaseContext;
import com.bt.enumeration.OperationType;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.time.LocalDateTime;

/**
 * @Description TODO
 * @Author 青
 * @Date 2023-04-15 16:58
 */
@Aspect
@Component
@Slf4j
public class AutoFillAspect {

    @Pointcut("execution(* com.bt.mapper.*.*(..)) && @annotation(com.bt.annotation.AutoFill)")
    public void aspect() {

    }

    /**
     * 前置通知 自动填充公共字段数据
     *
     * @param joinPoint
     */
    @Before("aspect()")
    public void autoFill(JoinPoint joinPoint) {
        log.info("开始自动填充公共字段数据..");

        //获取当前被拦截的数据库操作类型
        //获取方法签名对象
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        //获得方法上的注解对象
        AutoFill annotation = methodSignature.getMethod().getAnnotation(AutoFill.class);
        //获得数据可操作类型
        OperationType operationType = annotation.value();

        //获取到当前被拦截的方法的参数--实体对象
        Object[] args = joinPoint.getArgs();

        if (args == null || args.length == 0) {
            return;
        }

        Object arg = args[0];

        //准备赋值的数据
        LocalDateTime now = LocalDateTime.now();
        String currentId = BaseContext.getCurrentId();

        //根据当前不同的操作类型，为对应的属性通过反射来赋值
        if (operationType == OperationType.INSERT) {
            //为INSERT的4个公共字段赋值
            try {
                Method setCreateTime
                        = arg.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_TIME, LocalDateTime.class);
                Method setCreateUser
                        = arg.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_USER, Long.class);
                Method setUpdateTime
                        = arg.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);
                Method setUpdateUser = arg.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER, Long.class);

                //通过反射为对象属性赋值
                setCreateTime.invoke(arg, now);
                setCreateUser.invoke(arg, currentId);
                setUpdateTime.invoke(arg, now);
                setUpdateUser.invoke(arg, currentId);
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else if (operationType == OperationType.UPDATE) {
            //为UPDATE的2个公共字段赋值
            try {
                Method setUpdateUser
                        = arg.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER, Long.class);
                Method setUpdateTime
                        = arg.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);

                setUpdateTime.invoke(arg, now);
                setUpdateUser.invoke(arg, currentId);

            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    }
}


